Joint for rods



Patented Feb. 2s, 1928.

PATENT OFFICE.

RALPH PLUMB, 0F BUFFALO, NEW YORK.

JOINT FOB RODS.

Application led August 18, 1921. Serial No. 493,27*?.

My present invention relates to couplings for detachably securing together adjoining ends of rod sections and has its preferred application to the rod sections of drills used for boring deep holes of small calibre into the earth, such as oil, salt or artesian Wells. ll

An object of the invention is to provide a simple, inexpensive and durable coupling joint for the above purpose.

Another object of fthe invention is to provide an economical method for making rod coupling joints, which method can be executed without the use of skilled labor and which shall dispense with the Ieed for hot-working. t l

According to one feature of the invention, complementary male and female coupling members are used, each coupling member having a threaded socket engagement with the rod end to which it is se- `cured, the thread being preferably modified lhaving a complementary conformation.

According to another feature of the invention, the malleable steel coupling member has a plurality of small inwardly ex' tending lugs at localized parts of threads, fitting into corresponding depressions in the tops of the Frlod threads. l

-According to another feature of the invention one or more of the coacting threads of the rod and couplingmembers fextend laterally of the true' helical course at a. localized part. Preferably one of the threads is deflected toward` the lefty and another thread toward the right. ln the preferred embodiment the lugs are provided near the centers of the flattened areas of successive. threads and the'lateral deflection is applied at other threads.

Preferably, the socket member threaded onto the rod is provided with a squared exterior at which it can be readily grasped by a wrench forA tightening the coupling.

A desirable method for producing the coupling joint is by the simple application of a high pressure upon a definite localized portion of one side of the coupling member after the same has been threaded upon the rodend.

According to the preferred method, the socket member wit-h the rod threaded thereinto is inserted in a punch press provided with projecting dies, and pressure is applied to the cold metal at a localized portion ofone side of the squared portion to force the malleable steel of the coupling member inwardly to modify the helical course of the coacting threads in such manner as to offer obstruction against unthreading.

In the preferred embodiment, the die consists of a pair of projections of relatively small thickness, and substantial width, the

coupling member being inserted into the will further strike relatively sharp lugs inwardly from the tops of the socket threads of the coupling member to fit into corresponding depressions formed thereby in the tops of the rod threads. Furthermore, the

edges of the die will force the threads adjacent thereto laterally outwardly -to deect the same from their true helical course.

form of rod coupling,

Fig. 2 is a view in longitudinal section.'

I thereof,

Fig. 3 is an end view thereof,

' The end of the couplin Fig. 4 is a sectional view on an enlarged scale taken on the line 4-4 of Fig. 1,

Fig. 5 is a plan view of the interior of the coupling showing the thread modification,

Fig. 6 is a View similar to Fig. complementary portion, and;l

Fig. 7 is a sectional view taken on the line 7-7 of Fig. 1. f

Referring now to the drawings, 'I have shown a rod end 1 bearing a female coupling member 2 and a rod end 3 bearing a male coupling member 4, the coupling members having coacting threads 5, sol that they may be readily attached or detached from each other.

The coupling members are preferably of malleable steel/and are secured to their rods by a connection which will now beset forth, it being understood that the connections for the male and for the female coupling member are preferably identical. The end of the rod 1 is threaded as at 6 for a portion of the length thereof, several times the diameter. The malleable steel couplingmembers 2 and 4have socket ends 7 tapped as at 8 to accommodate th threaded rod ends',

member adjacent the tapped portion yis squared as at 9 to facilitate application of a wrench to tighten the coupling elements 2 and 4 together in connecting the drill rod sections.

In the preferred embodiment, the thread 5' of the is modified from its true helical course to prevent unscrewing. The description will be confined to the jointvbetween rod 1 and coupling 2, it being understood that the identical form of joint is usedfbetween rod 3 and element 4. Preferably the threads of theI y apparent that the lugs fitting in the depressions o ffer a positive obstruction against unthreadlng of the rod.l A pair of lthe coactling threads 15 and 17 on the socketand rod are preferably deflected or distorted laterally toward the left of the true helical course, and threads 16 and 18 are similarly deflected toward' the right, thus affording awedging .conformation to prevent turning of the rodI relative to the coupling in either direction. Preferably, also, the coacting flattened thread portions of 'some threads of the socket and the' rod are deflected inwardly as at 19 more than are other threads nearer the free end, thus affording a further wedging hold against unscrewing.

Although the flattening of the threads, the

`provision of the lugs on the socket fitting into corresponding depressions in the rod member, .the `lateral deflection or distortion of the threads from their true helical course and the extra inward deflection of certain .threads may be relied upon, each independetly of the other, for locking the threaded joint to prevent unscrewing, I prefer to elnploy all four features of the lock in combination.` f

In the preferred embodiment, the locking structure set forth is duplicated, being disposed at the two rectangular conformations -a pair of aligned punches corresponding to rectangular depressions 21 and 22 are employed. Pressure, is applied, driving the punches into the upper side 23 of the squared portion the proper depth to cause substantial flow of the metal supportin the threads thereby causing the threads o the coupling" to press with great force on the-t-hreads of' the rod. It is found upon cuttin open a coupling joint made in the manner escribed, that it has precisely the conformation shown in the drawings and heretofore described. The threads areY flattened as at 1() and 11, lugs 12 are formed/on the coupling threads fitting' into corresponding depressions 13 in the rod, threads 15-16and 17-18 are deflected'laterally out of their helical course, apparently bythe lateral 'flow Vof the metal displaced by the unch and the flattened area is bent mwar y as at 19. The cross-section of the rod is preferably not reduced or weakened at any point, the flattening and distortion being confined to the threads.

Except at the areas described, the coacting threads are preferably not deformed. It is seen that the force ofthe punch is transmitted to the base plate of the punchpress through the entire area of theV side 24 opposite the side 23 of thesquared coupling member upon which the die operated. Thus, the pressure is distributed through the socket and the rod along lines substantially those indicated in dot and dash in Fig. 3. The

cross-sectional' area over which the pressurey is applied, increasing from side 23 to side 24, thev pressure per unit area which is veriy high at the side 23 becomes Very much ess at side 24.l For this reason the thread yof the rod is modified at the side thereof adjacent the point of application of the die, while the lesser force per unit area transmitted to the lower portion of the rod will tend to force the rod thread into lintimate coaction with the thread in the malleable member without attenin or otherwise changing or distorting the t iread at these points.

By applying the pressure by two dies `1n alignment with each other, it will be seen that the formation of the'obstructions for the region corresponding to each of said dies is assured, an slight buckling of the metal of the socket etween or beyond the die depressions being of no consequence. The firm grip and the formation of the obstructions is thus assured by a plurality of successions of threads. e

The socket 25 of the female coupling mem.- ber is preferably deeper than the plug 26 of the male coupling member, so that the adjoining end surfaces 27, 28 of the coupling members can be brought into intimate contact with each other, as at 29 to relieve the stress upon threads '5 in the use of the drill and to prevent unscrewing.

By a destruction test, I have found that the rod coupling joint, shown and described,

.has enormous strength and that the gid itself will twist and bend under the application of high torque while the locked t read joint remains firm.

It will thus be seen that my method provides at small expense a wholly reliable joint, dispensing entirely with'the need for hot-working. Mere unskilled labor is required for expeditious production. Moreover, the construction does not require any differentiation between the formation of the rpd ends, which are simply threaded as noted, inidentical manner, the male and female coupling members bein secured at rod ends, by the simple metho set forth.

I claim:-

1. In a coupling for pump rods, in combination, a threaded rod end, a malleable coupling member having a tapped socket end threaded upon said rod end, a part'of the wall of the bore of said socket extending across threads on said rod and below the Itops thereof, said threads being correspond'- ingly indented to receive the inwardly extending part of the wall.

2. In a coupling for pump rods, in comblnatlon, a threaded rod end, a complementary malleable coupling member having a tapped socket threaded upon said rod end, means retalning said coupling against unthreading from the rod end including obstructions integral with said socket and longitudinabthereof and extending from the bore thereof inwardly, intimately into contact with a pluralit of threads on said rod and across the pat of unthreading movement, said threads being correspondingly end threaded u on said rod end, lugs at A `lopalized portions of certain of the threads on the couplingmember extending inwardlyv into correspon ng depressions in the coacta ing rod threads, one air of enacting threads on the rod and coup ing extending laterally of the true helical course toward one side,

and a second pair of coaoting threads on the rod and coupling extending similarly toward the opposite side.

4. In a coupling for pump rods, in combination, a threaded rod end, a malleable coupling member having av tapped socketend threaded upon said rod end, at least one of the coacting threads of the rod and coupling being vflattened and in intiiiiate Contact with each other, and lugs extending inwardly from said socket member at the center of said flattened portion into corresponding depressions in said rod threads.

5. In a coupling for pump rods, in combination, a threaded rod end, a malleable coupling member having a tapped socket end threaded upon said rod end, at least one of the coacting threads of both the rod and couplinglbemg flattened and in intimate contact 4wit each other, a pair of the coacting threads of the rod and coupling extending laterally of their true helical course.

6. ,In a coupling for pump rods, in combination, a threaded rod end, a malleable coupling member having a tapped socket end threadedl upon said rod'end, at least one of the coacting threads of the rod and coupling being flattened and in intimate contact with each other, a pair of the threads of the socket and rod at one side of said flattened portion belng deflected from their true helical course toward the left and a secondpair of threads at the opposite side of said flattened portion being similarly deflected towardthe right.

7. In a coupling for pump rods, in combination, a threaded rod end, a malleable cou-l pling member having a tapped socket end threaded upon said rod end, at least one of the coactingthreads of the rod and coupling being fiattened and in intimate contact with each other, a pair of the threads of the socket and rod at one side of said flattened portion being deflected from their true helical course toward the left and a second pair of threads at the oppositeside of said flattened portion being similarly deliected toward the right, and lugs extending inwardly from the center of said flattened porlili;

tion on said socket into corresponding depressions in the rod threads.

' 8. In a coupling for pump rods, in combination, a threaded rod end, a complementary malleable coupling member having a tapped socket threaded upon saidrod end, and means retaining said coupling member agalnst unthreadlng from the rod comprls ing obstructions integral with saiclsocket.

and forming a key extending across a plu- 10.

rality of threads of said rod, the said threads being correspondingly indented tof0rm a seat receiving said key.

Signed at Buffalo, in the county of Erie and State of New York, this 16th day of August, A. D. 1921.

RALPH PLUMB. 

